Work support for blind stitch sewing machines



April 30, 1940. H. F. GRUMAN 2,199,173

WORK SUPPO RT FOR BLIND STITCH SEWING MACHINES Original Filed April 12, 1957 6 Sheets-Sheet 1 s i. 5555mm: 0 WHERE-g I; f "y K w-T Q 4 4? :I N 0: lFF. "-3? mm MW WW W,

April 30, 1940. FKGRUMAN 2,199,173

WORK SUPIORT FOR BLIND STITCH SEWING MACHINES Original Filed April 12, 1937 6 Sheets-Sheet 2 April 30, 1940. GRUMAN 2,199,173

' WORK SUPPORT FOR BLI ND STITCH SEWING MACHINES Original Filed April 12, 1937 6 Sheets-Sheet 5 April 30, 1940.

H. F. GRUMAN W ORK SUPPORT FOR BLIND STITCH SEWING MACHINES Original Filed April 12, 1937 6 Sheets-Sheet 4 April 30, 1940. H. F. GRUMAN WORK SUPPORT FOR BLIND STITCH SEWING MACHINES 6 Sheet-Sheet 5 Original Filed April 12. 1957 Q I V April 30, 1940. H. F. GRUMAN WORK SUPPORT FOR BLIND S TITCH SEWING MACHINES Original Filed April 12, 1957 6 Sheets-Sheet 6 Patented Apri30, 1940 I i I a I v v v umro STAT-ES PATENT "o -Pics WORK SUPPORT FOR BLIND STITCH SEWING MACHINES.

Horace F. Gruman, St. Louis,.Mo.,"assi'gno r t I Geofifrey Stevenson Buffal N. Y. I g Original application April 12,1937, Serial No. 136,466. Divided and this application October .25, 1937, Serial No. 170,917 v 24 Claims. (Cl.'112-260) This invention relates to new and useful iming driven from the main shaft by v connections provements in sewing machines "generally, alindicated generally at In. A needle '-arm' il is though more particularly to the work support of fixed to the shaft '9 and attached to said arm, a blind stitch sewing machine; is a needle I2 which reciprocates across' the I' This application constitutes a division of my, presser foot opening. A looper l3 which cooper- 6 parent application Serial No. 136,466, filed April ates with the needle to form connected blind 12, 1937, for improvements in Sewing machines. stitches; is driven from the main shaft; 8 byn'con The principal object of this invention -is'to nections indicated generally at I4. 1 provide means for depressing as a unit thework Cooperating with the under face of the Jpresser clamp or support, the ridge forming element, and -foot B to clamp the fabric against the thrust of 10 the feed dogs whereby the work may be readily theneedle, is ahorizontal work clamp or sub inserted or withdrawn from the machine. iport C which'is rigidly secured along its right With the above-and other objects in view which hand edge to'th'e upper end of a vertical shank'or I will more fully appear, the nature of the ihvenpost l5 having avertical slot I6 formed therein. tion will be more clearly understood by follow- The workclampis provided with three parallellfi, ing the description, the appended claims, and and longitudinally extending feed-slots of equal the several views illustrated in theaccompany: length, there-being two side slots ll, it and an ing drawings. 7 interrupted intermediate slot comprising a front In the drawings: 7 r l 7 portion IS, a rear portion 23, and an interme- Figure 1 is a front elevation of a sewing madiate chaining-01f bridge 2|. The interme- 29 chine constructed in accordance with my invendiate slot is centered with respect to the opening tion, I in the'foot, and the side slots ll, [8 are ilocated Figure 2 is a left end elevation thereof, 7 on opposite sides of said opening.- These slots Figure 3 is a rear elevation of the machine, extend from a point in front of the needle path I Figure 4 is a vertical section taken through to a point well in rear'thereof. The work clamp the frame standard; is supported, on the lower frame arm 1 for'ver Figure 5 is a vertical longitudinal section taken 'tical movements with respect to the presser foot, through the lower frame arm, and to this end the shank l5'is supported for Figureo is a horizontal section taken onthe slidable movements between vertical guides 22, 80 line 6-6 of Figure 1, 23, the guid'e22ibeing a part of theend 'wall 24 Figures 7 and 8 are detail views showing' 'the of said lower frame arm I, and the guide 23' driving connection for the feed lift rock shaft, being 'removably mounted on said wall. ,The end Figure 9 is an enlarged perspective view of the wall 24 between said guides is provided with a work clamp, g vertical slot 24a-and fixed to the shank "and Figure 10 is anenlarged side elevation of the projecting through'the slot into the interior of 5 ridge forming disc, the' frame arm, is an abutment or arm 25 hav- Figure 11 is a vertical section taken on the line ing a 1 depending pilot stud 26. I An adjusting ll-ll of Figure 10, and r w screw 2! is threaded upwardly into thepottom Figure 12 is a horizontal section taken on. the 'wall 28 of the frame arm I directly below the; 49 line l2l2 of Figure 10. I I stud 26, and a coil spring 29 is interposed be- 40 Like reference numerals designate correspond tween the stud and the screw for yieldably urging parts throughout the several figures of the ing the work clamp upwardly and for normally drawings. 1 j v g y retaining said clampin yieldablev engagement The sewing machinewhich embodies my in- 'with'thepr'esser foot. In orderto depress the vention includesa main frame A having a 1101- work clamp-Cagainst the tension of the spring 45,

low standard 5 and upper and lower hollow arms 29, I have provided'a treadle or knee-press oper- 5 and 1 which extendlaterally from the left side ated chaintll which vextends upwardlythrough of the standard. A main shaft a extends longian opening 3Iin the bottom wall 28 o'f'the frametudinally along. the upper arm 6 and across the l and is connected indirectly at its upper end to standard 5. .Ahorizontal presser foot 13 having the work clamp,' as will be explained hereinafter. an opening, is rigidly attached to the free end of Cooperating with the under face of the presser the upper arm 6. An oscillatory horizontal foot 13 to feedthe fabric rearwardly are a 4'- needle shaft 9 extends at right angles to the motion main feeddog 32 and a -motiondiffer main shaft8 and is journaled in the upper'arm ential feed dog 33. The main feed dog .32 in- 6 above thepresser foot B, said needle shaft be 7 eludes two long side sections 34, 35 and a short mounted in a forked rock arm 49.

intermediate section 31 which operate in the rear portion of the feed slots of the work clamp. The side sections are disposed on opposite sides of the presser foot opening and extend forwardly to a point slightly in front of the needle path, but the intermediate section is disposed wholly in rear of the needle path and in rear of said opening. The differential feed dog includes two long side sections 38, 39 and a short intermediate section 40 which operate in the front portions of the feed slots in the work clamp. The side sections'34, 38 and 35, 39 of the feed dogs are arranged in overlapping relation for engaging the body fabric throughout the combined length of both dogs.

The differential feed dog 33 is attached to the upper end of a vertically.,,disposed differential feed bar 4! which is fulcrumed at its lower end as at 42 to the front arm 43 of a horizontal feed lift lever 44 which is fulcrumed as at .45 on the shank ii of the vertically movable work clamp C. Pivotally mounted on the rear arm 46 of the lever as at 47 is a slide block 48 which is slidably The arm 49 is fixed to and extends from a feed lift rock shaft 50 which is journaled in the rear portion of the lower frame arm I. The shaft 50 is provided with a rock arm located within the frame arm I and this arm is oscillated from a horizontal countershaft 52, which extends lengthwise of the arm and across the standard, by a pitman 53 which is pivotally connected at its lower end to the rock arm and has its upper end engageable with a driving eccentric 54 fixed to'said countershaft as shown in Figs. 7 andii. The shaft 52 is driven from the main shaft 8 by a l-to-l gear coupling located within the standard 5 and comprises a driving gear 55 fixed to the main shaft, a driven gear 56 fixed to the driven countershaft 52, and an intermediate gear or idler 51 journaled on the standard. Although I have specifically shown and described a gear coupling between the main shaft 8 and the countershaft 52, any other known mechanical driving means having a l-to-l ratio may be employed and I thereforeuse the term gear coupling in its broadest sense. Thus during each rotation of the main shaft the differential feed dog will be raised and lowered. Journaled in the lower frame arm 7 in rear of the rock shaft 50 is a differential feed travel rock shaft 58 which is actuated from the driven shaft 52 by means of a-rock arm 59 located within the lower frame arm 1 and fixed to the shaft 58, and a pitman 6!! which is pivotally connected as at 6! to said rock arm and has operative connection with the driven shaft through the medium of an adjustable eccentric fixed to said driven shaft and indicated as an entirety by the numeral 62. Fixed to the left hand end of the rock shaft 58 is. a rock arm 63 and a horizontal link 64 is pivotally connected at its rear end as at 65 to said rock arm and is pivotally connected at its front end to a stud or pin Bfifixed to the differential feed bar 4|. Consequently a back and forth movement will be imparted to the differential feed dog 33 during each rotation of the main shaft, and by adjusting the eccentric 62 the feed stroke of the dog may be varied.

The main feed dog 32 is'atta'ched to a forwardly and slightly downwardly inclined main feed bar 67. I 'he front end of the bar is provided with a fork 68 which has sliding engagement with the pin 66' fixed to the differential feed bar 4i and consequently the front end of the main feed bar is supported by and moves upwardly and downwardlywith said differential feed bar. The

rear end of the main feed bar 67 is pivotally connected as at 69 to a rock arm TB fixed to a sleeve or tubular feed travel shaft H which surrounds the differential feed travel shaft 58. A rock arm 12 is fixed to the tubular shaft 7! and this arm is oscillated from the driven countershaft 52 by a pitman 13 which is pivotally connected as at M- with said rock arm and has operative connection with the driven shaft through the medium of an adjustable eccentric fixed to said driven shaft and indicated as an entirety by the numeral 75. Consequently a back and forth movement will be imparted to the main feed dog during each rotation of the main shaft, and by adjusting the eccentric T5 the feed stroke of the dog may be varied.

From the foregoing, it will be seen that both feed dogs are moved upwardly and downwardly in unison, and that the feed travels of the dogs are independently adjustable.

In the operation of the feeding mechanism, let it be assumed that the differential feed bar 4! is beginning its upward stroke. The lever 44 is rocked about its fulcrum. 45 and the feed bar is lifted until it engages the under face of the presser foot. The lever 44 then shifts its fulcrum to the pin 62 and consequently the original fulcrum 45 is moved downwardly taking the work clamp C therewith. This frees the fabric from its clamped condition between the foot and the work clamp, and permits the feed dogs to function. At the end of the feed stroke, the original fulcrum is moved upwardly while the auxiliary feed bar is moved downwardly, whereby the work clamp will be restored to its initial clamping position.

Projecting upwardly through the front intermediate opening IQ of the work clamp and into the opening of the presser foot is a ridge forming element D for presenting a ridge of fabric to the needle. When hemming operations are being performed the ridge will include the body fabric and the inner edge portion of the hem.

Located within the lower frame arm 7 is a rotary shaft 16 whose longitudinal axis lies in the vertical plane containing the needle path of movement. This shaft is journaled in spaced right and left bearings 1?, ll of a lever arm 18 which is provided at its inner end with a transverse horizontal bearing 19 journaled on a stud 80 fixed to the front wall 8! of the frame arm I. The outer or left end portion of the shaft projects through the slot E ia of the end wall 24 of the lower frame arm 1 and through the vertical slot it of the shank 15 of the work support 0, and is provided at its outer end with an inwardly extending counterbore 82 and a threaded bore 83. The ridge forming element D, as shown in Figs. l0, l1 and 12, is in the nature of a star disc, and this disc is. provided with an integral hub 84 which is received by the counterbore 82 and the hub is provided with an integral threaded pin or reduced extension 85 which is threadably engagedin the bore 83 whereby the disc may be readily removed. The disc shaft 15 is pressed upwardly by a spring 86 located intermediate the supporting lever arm 18 and the bottom wall 28 of the lower frame-arm 1, and a manually operable screw 81 which is threaded downwardly into the top wall 88 of the lower frame arm 1 engages said lever arm and thereby enables the operator to vary the effective height of the disc relative to the needle path, the spring also functioning to permit the disc to be automatically lowered when seams or thicker fabrics are fed through the machine. The disc shaft I6 is continuously rotated from the countershaft 52 by a driving connection which in the present instance includes a reduction gear coupling having a 4-to-1 ratio. Although, I have specifically shown and described a gear coupling between these shafts, any; other known mechanical reduction driving means may be employed and I therefore use the term reduction gear coupling in its broadest sense. To this end, a relatively small gear :89 which is fixed to the countershaft 5.2 within the frame standard 5, drives a relatively large gear 90 which is loose on a stub shaft 91 fixed to the standard, the ratio being Z-to-l. Fixed to the geartfl is a gear 92 of the same diameter as the gear 89., and this gear e2 drives a gear .93 which is loose on the counters-heft 52, the ratio ofthe gears 92, 93 being l-to-Z. Fixed to the gear 93 is a gear '94 and fixed to the disc shaft 'lfiadjacent the transverse pivot 39 thereof is a gear 95 which is in constant mesh with the driven gear 94, the ratio of the gears $4, 95 being l-to-l, and'consequently the disc will be rotated once during every four revolutions of themain shaft. The teeth of the gears 94, 95 are so construoted as to permit the upward and downward swinging of the disc shaft 86 without any binding.

The upper end of the chain 30 previously described is connected-to the free end of the lever arm 18 which supports the disc shaft 16. An interponent or bar 96 is mounted in ahorizontal groove 91 formed in the shank H: of the work clamp C for sliding movements across the vertical opening N5 of said shank, the interponent being formed along its upper edge with a recess 9B. The interponent is retained in its groove or seat 9'1 by a flat spring 99 attached to the opening fill is formed in the forward end of the interponent for facilitating the forward movement thereof. The disc shaft I6 projects through the slot 46 above the interponent. 'When the interponent is in its forward position the recess QByvill not register with the slot l6 and consequently the disc shaft when depressed by the chain 3Ilwi1l engage said interponent and thereby depress thework clamp together with the feed so as to permit the ready insertion of fabric in the machine, or removal therefrom. 1 When, however, it is desirable toremove the ridge forming element D from the shaft 16 for the purpose of substituting another element, it is necessary to provide means for lowering the element below the presser foot and the work clamp in order for the element to clear the latter, and for this purpose the interponent 96 is moved rearwardly until the-recess 98 therein registers with the open ing, I6 073- the shank l5 of the work clamp. The operator can then depress the shaft 16 "into the recess 98 and thereby position the disc D entirely below the work support whereby: the disc'may be readily removed from theshaft and another disc substituted thereon.

1 It will, therefore, be seen that the shaft 16 is substantially horizontal at all times; that byhaving the fulcrum 19, 80 located within the frame standard 5 the shaft 16 will form a long radius for the ridge forming element D and conment; that the upper portion of saidelement normally projects upwardly through the opening l! to remove the element from the shaft it is necessary toiswing the shaft downwardly until the element clears the work clamp; that when the interponent 96 is in itsr'earmost position, the shaft. may be swung downwardly by a pull on the chain 30 without depressing the work clamp and the feed, andthat when the interponent is in its foremost position the'work clamp, the feed, and the element will be depressed by a pull on the chain to thereby permit theready insertion of work into the machine or the removal of work therefrom. It is of course to be understood that the details of structure and arrangement of parts'may be variously changed and modified without departing from the spirit'and' scope of my invention.

I claim:

1'. In a sewingmachine, the combination with a stationary horizontal presser' foot, of a vertically movable work clamp located below the swinging the shaft to depress the ridge forming element and for simultaneously effecting a depression of thework clamp.

2. In a sewing. machine, the combination with a stationary horizontal presser foot, of a vertically movable work clamp located below the foot,

' spring means for yieldably retaining the work clamp against depression, a ridge forming element for projecting a. ridge of fabric upwardly through the foot, a horizontal shaftsupporting said element and formed in a single rigid length, means independent of said'work clamp for supporting. the" shaft for movement about its axis.

and for swinging movement about a transverse axis, a stop' for limitingthe upward swinging 1 movement of the shaft, spring means for yieldably retaining the shaft against-depression, and means for swinging the shaft to depress the ridge forming element and. for simultaneously effecting a depression of the work clamp.

3. In a sewing machine, the combination with a stationary horizontal presser foot, of a vertical- 1y movable work clamp located below the foot, a ridge forming element for projecting a ridge of fabric upwardly'through the foot, a horizontal shaft supporting said element and formed in a single rigid length, means independent of "said work clamp swingable about a transverse axis and constituting the sole means fors'upporting the shaft for rotary movement, means for rotating said shaft, and means for effecting a simultaneous depression of thework clamp and a swinging of the shaft todepress the ridge forming element without disconnecting said shaft ro- I tating'means,

4. In a sewing machine, the combination with a stationary horizontal presser foot, of avertically movable work clamp located below the foot, a ridge forming element for projecting a ridge of fabric upwardly through the foot, a horizontal shaft supporting said element formed in a single rigid length and fulcrumed to swing about a transverse axis,.1neans for continuously rotating said shaft includinga driven gear fixed thereto,

andr'neansTfor'swinging' the shaft to depress the ridge forming element without disconnecting said shaft rotating means and for simultaneously depressing the work clamp.

5. In a sewing machine, the combination with a stationary horizontal presser foot, of a vertically movable work clamp located below the foot, a horizontallever arm fulcrumed to swing about a transverse axis, a shaft extending longitudinally of said arm and journaled therein, a ridge forming element attached to the outer end of the shaft for projecting a ridge of fabric upwardly through the foot, and means connected to said arm for swinging the shaft downwardly to depress the ridge forming element and for simultaneously depressing the work clamp.

6. In a sewing machine, the combination with a stationary horizontal presser foot, of a vertically movable work clamp located below the foot, a ridge forming element for projecting a ridge of fabric upwardly through the foot, a horizontal shaft supporting said element and fulcrumed to swing about a transverse axis, means movable between effective and ineffective positions forming an abutment between the shaft and the work clamp, and means for swinging the shaft to depress the ridge forming element and for simultaneously depressing the work clamp.

7. In a sewing machine, the combination with a stationary horizontal presser foot, of a vertically movable work clamp located below the foot, a horizontal lever arm fulcrumed to swing about a transverse axis, a shaft extending longitudinally of said arm and journaled therein, a ridge forming element attached to the outer end of the shaft for projecting a ridge of fabric upwardly through the foot, means forming an abutment between the shaft and the work clamp, and means connected to said arm for swinging the shaft downwardly to depress the ridge forming element and for simultaneously depressing the work clamp.

8. In a sewing machine, the combination with a frame including a standard having upper and lower arms extending laterally therefrom, of a horizontal presser foot fixed to the'free end of the-upper arm, a work clamp located below the foot and supported on the free end of the lower arm for vertical movements, a horizontal shaft extending longitudinally within the lower arm and pivoted therein to swing about a transverse axis, the outer end of the shaft projecting under the work clamp, a ridge forming element attached to the outer end of the shaft for projecting a ridge of fabric upwardly through the foot, and means for swinging the shaft to depress the ridge forming element and for simultaneously depressing the work clamp.

9. In a sewing machine, the combination with a frame including a standard having upper and lower arms extending laterally therefrom, of a horizontal presser foot fixed to the free end of the upper arm, a work clamp located below the foot and supported on the free end of the lower arm for vertical movements, spring means for ably retaining theshaft against depression, and means for swinging the shaft to depress the ridge forming element and for simultaneously depressing the work clamp.

10. In a sewing machine, the combination with a frame including a standard having upper and lower arms extending laterally therefrom, of a horizontal presser foot fixed to the free end of the upper arm, a work clamp located below the foot and supported on the free end of the lower arm for vertical movements, a horizontal shaft extending longitudinally within the lower arm and pivoted therein to swing about a transverse axis, the outer end of the shaft projecting under the work clamp, a ridge forming element attached to the outer end of the shaft for projecting a ridge of fabric upwardly through the foot, means forming an abutment between the shaft and the work clamp, and means operatively connected with the shaft for swinging the latter to depress the ridge forming element and for simultaneously depressing the work clamp.

11.. In a sewing machine, the combination with a frame including a standard having upper and lower arms extending laterally therefrom, of a horizontal presser foot fixed to the free end of the upper arm, a work clamp located" below the foot and having a depending vertical shank supported on the free end of the lower arm for vertical sliding movements, said shank having an opening therein, a shaft extending longitudinally within the lower arm and pivoted therein to swing about a transverse axis, the outer end of the shaft projecting through the opening in said shank and having abutment with the latter, a ridge forming element attached to the outer end of the shaft for projecting a ridge of fabric upwardly through the foot, and means for swinging the shaft to depress the ridge forming element and for simultaneously depressing the work clamp.

12. In a sewing machine, the combination with a stationary horizontal presser foot, of a vertically movable work clamp located below the foot, a ridge forming element for projecting a ridge of fabric upwardly through the foot, a horizontal shaft removably supporting said element and fulcrumed to swing about a transverse axis, and means for either swinging the shaft downwardly to depress the ridge forming element and for simultaneously depressing the clamp or for swinging the shaft downwardly without depressing the clamp for facilitating the removal of said ridge forming element.

13. In a sewing machine, the combinationwith a stationary horizontal presser foot, of a vertically movable work clamp located below the foot, a ridge forming element for projecting a ridge of fabric upwardly through the foot, a horizontal shaft removably supporting said element and fulcrumed to swing about a transverse axis, and means including an interponent between the clamp and the shaft for swinging the shaft to depress the ridge forming element and for simultaneously depressing the clamp, said interponent being movable to a position to effect the downward swinging of the shaft without depressing the clamp for facilitating the removal of said ridge forming element.

14. In a sewing machine, the combination of a stationary presser foot, an independently movable work clamp opposed to said foot, a ridge forming element for projecting a ridge of fabric upwardly through the foot, a horizontal shaft supporting said element and fulcrumed to swing about a transverse axis, and meansfor effecting a swinging of saidshaft and a depression of said element with or independently of said work clamp.

15. In a sewing machine, the combination of a stationary presser foot, an independently movable work clampopposed to said foot, a ridge forming element for projecting a ridge of fabric upwardly through the foot, a horizontal shaft supporting said element and fulcrumed to swing about a transverse axis, a stop for limiting the upward swinging movement of the shaft, independent spring means for yieldably retaining the shaft and the work clamp against depression, and means for effecting a swinging of said shaft and a depression of said element with or independently of said work clamp.

16. In a sewing machine, the combination with a stationary presser foot, of a ridge forming element for projecting a ridge of fabric upwardly through the foot, a horizontal shaft rigid throughout its length supporting said element and fulcrumed to swing about a transverse axis,

- means including intermeshing gearsfor rotating said shaft, one of said gears being mounted directly on said shaft, and means for swinging said shaft to depress said element without disconnecting said shaft rotating means.

17. In a sewing machine, the combination with a stationary presser foot, of a ridge forming element for projecting a ridge of fabric upwardly through the foot, a horizontal lever arm fulcrumed toswing about a transverse axis, a shaft .the shaft against depression, means connected to the arm for swinging the shaft downwardly to depress the ridge forming element, and shaft driving means including a driven element mounted on and swingable with the shaft.

18. In a sewing machine, the combination with a stationary presser. foot, of a ridge forming element for projecting a ridge of fabric upwardly through the foot, a horizontal leverarm fulcrumed to swing about a transverse axis, a shaft rigid throughout its length extending longitudinally of said arm and journaled therein, a ridge forming element attached to the outer end of the shaft for projecting a ridge of fabric upwardly through the foot, means for continuously rotating said shaft including a driven gear fixed to the shaft, a stop cooperating with the arm to limit the upward swinging movement of the shaft, spring means cooperating with the arm for yieldably retaining the shaft against depression, and means connected to the arm for swinging the shaft downwardly to depress the ridge forming element without disconnectng said shaft rotating means.

19. In a sewing machine, the combination with a frame including a standard having upper and lower arms extending laterally therefrom, of a horizontal presser foot fixed to the free end of the upper arm, a horizontal shaft rigid throughout its length extending longitudinally within the lower arm and supported to swing about a transverse axis located within the standard, the outer end of the shaft being located under the presser foot, a ridge forming element attached to the outerend of the shaft for projecing a ridge of fabric upwardly throughrthe foot, spring means cooperating with the shaft for yieldably urging the ridge forming element upwardly, a vertically adjustable stop. for limiting the upward swinging movement of the shaft and. a gear couple for rotating saidshaft including a gear fixed to said shaft. v

20. In a sewing machine, the combination with a frame including a standard having upper and lower arms extending laterally therefrom, of a horizontal presser foot fixed to the free end of the upper arm, a horizontal shaft rigid throughout its length extending longitudinally within the lower arm and supported to swing about a transverse axis located within the standard, the outer end of the shaft being located under the presser feet, a ridge forming element attached to the outer end of the shaft for projecting a ridge of fabric upwardly through the foot, spring means 21. In a sewing machine, the combination with I a stationary horizontal presser foot having an opening, of a Work clamp located below the foot and having an opening, a horizontal shaft fulcrumed to swing about a transverse axis and having one end disposed below the work clamp,

a ridge forming element removably connected to said end of the shaft and normally having its 22. In a sewing machine, the combination with" a stationary horizontal presser foot having an opening, of a work clamp located below the foot and having an opening, a horizontal shaft fulcrumed to swing about a transverse axis and having one end disposed below the work clamp, a-

ridge forming element removably connected to said end of the shaft and normally having its upper portion projecting upwardly through the opening in the clamp and into the p-resser'foot opening, spring means cooperating with the shaft for yieldably urging the ridge forming element upwardly, a vertically adjustable stop for limiting the upward swinging movement of the shaft, and means for swinging the shaft downwardly to depress the ridge forming element to a position per portion projecting upwardly through the opening in the clamp and into the presser foot opening, said element comprising a disc having angularly spaced peripheral portions arranged in tandem, the disc being provided with a concentric hub terminating in a reduced threaded pro-- J'ection, the end of the shaft being formed with a counterbore for receiving said hub and with a threaded bore for receiving said extension, and

means for swinging the shaft downwardly to depress the ridge forming element to a position wholly below the clamp whereby said element may be removed.

24. In a sewing machine, the combination with a stationary horizontal presser foot, of a vertically movable work clamp located below the foot, a 4-motion feed dog supported on the work clamp, 

